Originally Posted by PepeLapiu
You have debunked my issue with PWM fairy well Jack.
Still an other issue makes PWM control not optimal for WC'ing:
Your CPU temps will fluctuate a lot faster than your water temps.
This would cause your fan curve to be a lot more abrupt and noticeable.
I just find that the extra cost of PWM fans isn't worth it.
Most good PWM fans will have a price around or above GT fans.
So you end up paying more money for fans that aren't as good at GT fans. And the controlling of them is not optimal either.
I think you knew what you were doing .... just the way it was reading, was coming across well.
I haven't seem the fan speeds changing that much .... in fact one of the things stuck in my head now .... and this will shock you..... I'm debating whether fan control is worth my T & E. Look at it this way:
1. My fans are dead silent at 850 rpm
2. My fans never go above 850 rpm
So why not just leave them at 850 rpm ?
I have I spent hours upon hours testing and tweaking fan curves ..... cause like you, I'm a geek ..... it's not about whether I need it, it's about the challenge of tweaking it to the best possible condition .... it's fun.
PWM from an engineering / efficiency standpoint is better .... the obligatory geek statement being made, from a practical standpoint, it just doesn't matter.....and if ya saving $5 per fan for $16 fans, that gets you from a 770 to a 780 and that certainly is practical. With MoBo manufacturers moving to 4 pin headers, i think it's just a matter of time before they are PWM .... I'm gonna assume at least that at some point, some MoBo manufacturer will want to distinguish themselves and actually make those OPT_1 thru OPT_3 temp sensors control those OPT_1 thr OPT_3 fans.
But here's where it gets attractive.....Your MoBo headers are curtailed by low amp readings, typically 1 watt. However, if this fan header was PWM, true PWM, then you could feed a Phanteks PCB which can handle 11 fans. The PCB has a PSU connector to supply extra voltage if ya need more than the header can provide..... however, if its voltage contolled header, then the 12V PSU feed will override that. However if it's PWM, then it works just fine.